Languages are a beloved subject of debate and the kernels of some of the strongest developer communities. The choice of programming language matters deeply to developers because they want to keep their skills up to date and marketable. They matter to toolmakers too, because they want to make sure they provide the most useful SDKs. So which programming languages had notable changes in adoption trends in the last 3 years?

We've shared the answers in our infographic with key findings from our Developer Economics 19th edition survey, which ran in June-August 2020 and reached 17,000 developers in 159 countries. If the infographic below looks a little small for you, take a look at it here.

JavaScript is the most popular programming language

As of Q3 2020, 12.4M developers globally were using JavaScript. We also estimate that in mid-2020 there were 21.3M active software developers in the world. So, 58% of all developers use JavaScript. Notably, the JavaScript community has been growing in size consistently for the past three years. Between Q2 2017 and Q3 2020, nearly 5M developers joined the community – by far the highest growth in absolute terms across all languages. Even in software sectors where JavaScript is least popular, like data science or AR/VR, over a fifth of developers use it in their projects.

It’s a good idea to learn Python

For the second half-year period in a row, Python is the most widely adopted language behind JavaScript. Python now counts 9M users, after adding 2.2M net new developers in the past year alone, outranking Java at the beginning of 2020. The rise of data science and machine learning (ML) is a clear factor in its popularity. An impressive 77% of ML developers and data scientists currently use Python. For perspective, only 22% use R, the other language often associated with data science.

What’s new with Java and other well- established programming languages?

Java, with over 8M active users worldwide, is the cornerstone of the mobile app ecosystem – Android – as well as one of the most important general-purpose languages. It’s adoption may have remained stable in the past six months but, in the overall picture, the Java community has gained 1.6M developers since mid-2017, which corresponds to a 24% growth.

The group of major, well-established languages is completed with C/C++ (6.3M), PHP (6.1M) and C# (6M). The fact that C# lost three places in the ranking of language communities during the last three years is mostly explained by its slower growth compared to C/C++ and PHP. C and C++ remain core languages in IoT projects (for both on-device and application-level coding), whereas PHP is still the second most commonly used language in web applications, after JavaScript. On the other hand, C# may be sustaining its dominance in the game and AR/VR developer ecosystems, but it seems to be losing its edge in desktop development – possibly due to the emergence of cross-platform tools based on web technologies.

Android developers behind Kotlin growth

Kotlin is one of the fastest growing language communities, having increased more than two-fold in size since the end of 2017, from 1.1M in Q4 2017 to 2.3M in Q3 2020. This is also very evident from Kotlin’s ranking, where it moved from 11th to ninth place during that period – a trend that’s largely attributed to Google’s decision to make Kotlin its preferred language for Android development.

Swift surpassed Kotlin in popularity this year, after attracting slightly more net new developers in the first half of 2020 (400k vs 300k). Since Swift became the default language for development across all Apple platforms, the adoption of Objective C has been decreasing steadily. This phase-out from the Apple app ecosystem is also matched by a significant drop in the rank of Objective C, from ninth to 12th place.

Finally, the more niche languages – Go, Ruby, Rust, and Lua – are still much smaller, with up to 1.5M active software developers each. Ruby and Lua have been around for more than two decades now, but their communities have essentially stopped growing in the last three years. On the contrary, Go and Rust appear to be actively adding developers, although it is still unclear whether the two languages will climb the programming language ranking in the coming period.

What’s your favourite programming language? Take our Developer Economics 20th edition survey to support your choice!